TFEB Modulates p21/WAF1/CIP1 during the DNA Damage Response.

The MiT/TFE family of transcription factors (MITF, TFE3, and TFEB), which control transcriptional programs for autophagy and lysosome biogenesis have emerged as regulators of energy metabolism in cancer. Thus, their activation increases lysosomal catabolic function to sustain cancer cell growth and survival in stress conditions. Here, we found that TFEB depletion dramatically reduces basal expression levels of the cyclin-dependent kinase (CDK) inhibitor p21/WAF1 in various cell types. Conversely, TFEB overexpression increases p21 in a p53-dependent manner. Furthermore, induction of DNA damage using doxorubicin induces TFEB-mediated activation of p21, delays G2/M phase arrest, and promotes cell survival. Pharmacological inhibition of p21, instead, abrogates TFEB-mediated protection during the DNA damage response. Together, our findings uncover a novel and direct role of TFEB in the regulation of p21 expression in both steady-state conditions and during the induction of DNA-damage response (DDR). Our observations might open novel therapeutic strategies to promote cancer cell death by targeting the TFEB-p21 pathway in the presence of genotoxic agents.